To avoid harming people or the planet, fix the leaks, get better data and build better wells.

New York state has a moratorium on hydraulic fracturing. So do Los Angeles, Quebec and France. Polls show rising opposition to this controversial oil field technique, which cracks open rocks to free oil and natural gas, and some critics want it banned unless it can be proven safe.

Meanwhile, U.S. energy companies are drilling and fracking about 100 wells every day across much of the country. Whether you think that it is an economic...